It can't be much worse than exposure to the chemicals in most of our cleaning products.
(Strictly speaking, I think there needs to be a volcano involved to create the fine particled silica relevant to that disease, but how often do you get a chance to naturally work it into conversation?)
(I've always been disappointed that it's "...microscopic..." rather than "...microscopo...", which seems rather unnatural.)
In smaller doses it would cause Silicosis.
For this reason this will never be sold to consumers, although it might be used in a factory, but only with very strict controls.
Does it have to be sprayed? Because that will never go on the market. But a brush on version might.
This product wouldn't cause silicosis when used correctly, even if it does it'll have to exceed the percentages reached by long-time cement layers to be concerning. So really, why can't you see it being approved? Do you know of a legitimate reason, or is it a personal opinion?
I've worked in construction, I've had my hands blister from some materials I've used yet you can pick them up at any hardware store without question. There's no instruction on fiberglass insulation that states face masks must be worn despite its fibers can cause rhinitis and lung irritation.
Hell, Talcum Powder with over exposure can have the same effects on the lungs as asbestos and it's used daily by millions on their infants.
There's many things approved for the general public that are exceptionally dangerous when they're being used correctly. There's an even bigger list for when things are being used incorrectly, even down to detergents.
It's exceptionally easy to manifest the danger, and I bought the bottle for 3 pounds.
In any case, their primary target seems to be businesses that want to add value by adding a highly dirt-resistant finish to their products.
Hell, superglue is likely as hazardous if used improperly. I've seen cotton overalls lit on fire by someone dumping a bottle, and I was handed it in primary school! Cement is dangerous to the skin and lungs, especially mixing dry cement as the lime can actually cause chemical burns to your lungs, or you can develop silicosis over longterm exposure, hence face-masks.
There'll obviously be precautions that have to be taken. However it all depends on droplet size formed by the spray. A fine spray is unlikely to reach or coat a surface appropriately, so I'm assuming a heavier spray intended to coat a specific area. This means larger droplets and less spread of the spray, it also decreases the likelihood that it'll get through a face mask making a respirator less likely.
If it can be used with a simple face mask, it'll be on sale in the UK without a doubt.